New Features in Visual Prolog 6.2

Visual Prolog 6.2 comes with a completely new object-oriented PFC GUI library, a much improved COM support, and a dozen of other improvements in Visual Prolog compiler, Prolog Foundation Classes (PFC), Setup, and in the Visual Development Environment (VDE).

PFC GUI

The PFC GUI library is an object-oriented GUI library similar in style to the GUI framework in .NET. Windows, dialogs, forms, and controls are implemented as objects. This strategy is simple and powerful. The new GUI package co-exists with an old style VPI to such extent that a program can have dialogs both in an old VPI style and in a new PFC GUI style. It is therefore possible to have a gradual transition from the old style to the new style. We are confident that the benefits of the PFC GUI library eventually will motivate you to rewrite your old dialogs, but until then your old VPI dialogs will keep working.

Windows, controls, etc. are manipulated directly by invoking predicates on the objects instead of using window handles. Events are handled by registering listeners and responders directly on the controls and windows, rather than being handled by a "global" event handler for the entire dialog. Custom controls are used in exactly the same way as standard controls. It is now much simpler to implement your own custom controls.

PFC GUI is supported by the Dialog Editor in the Visual Development Environment (VDE). Controls can be grouped in container controls. Such possibility simplifies dialog layout updates.

Some of the new features in PFC GUI are:

forms;
a possibility of grouping controls in container controls that simplifies dialog layout.

For details see the PFC GUI package overview.

COM Support (only in the Commercial Edition)

If you want to use a COM component in your project, the VDE can create a COM package for the component. The VDE will then generate proxy classes allowing you to access the COM class instances as a normal Visual Prolog objects with normal Prolog predicates. The proxy classes also handle the lifetime of COM objects, releasing the COM instance, when the proxy object is reclaimed by the garbage collector.

If the COM component is an Active/X control, the VDE detects this and generates additional Active/X support for the control. With that support you can use the control as any other PFC GUI control.

The COM support only provides a limited support for outgoing interfaces, i.e. the interfaces that are implemented in Visual Prolog and are exposed to surroundings. This implies that there is no support for generating code for creating COM components or for registering event sinks with imported components, i.e. such possibilities should be programmed manually.

Other New Features

Compiler

the export keyword has been added to export all predicates in a class into a DLL.
New predicates:
- The isErroneneous predicate to check fact variable;
- arithmetic predicates quot and rem
Visual Prolog 6.2 Compiler generates warnings for the features, that will not be supported in Visual Prolog 7.

PFC

Boolean package
The boolean package contains:
- class predicates to perform conversions from boolean domain to core::booleanInt domain and vice versa.
- several class predicates for logical operations: OR, AND, XOR, NOT.
Template package (only in the Commercial Edition)
The template package contains a class for handling templates.
IsApi package (only in the Commercial Edition)
The package supports development of the ISAPI extensions for Microsoft Internet Information Server
ActiveXcontainer package (only in the Commercial Edition)
GUI package
Support for the system tray
Many small improvements

VDE

A possibility to add necessary include files while building, based on the requires directive in PFC and user packages.
Templates for newly generated interfaces, classes, implementation.
The Menu Editor can now show the entire menu as a tree.
Container controls are supported by the Dialog Editor.
A possibility to show current facts in the Variable window in a debugger session.
Improved speed.
The Editor Cursor now shows a copy or move mode.
Many small improvements.

Setup

Setup now handles Visual Prolog runtime DLLs